This invention relates generally to photography and more particularly to film holding apparatus for large format sheet film.
It is well known that large format photography has several advantages, most of which flow from the high quality of the resulting photographs taken in this format. This high photographic quality comes at a high price, however. That price includes not only the weight and size of the large format field camera or view camera itself, but also the great weight and bulk of the large quantity of large format sheet film the photographer must carry.
For large format sheet film to be readily useful, every single sheet of film must be loaded into a film holder. Examples of such film holders are shown in the following U.S. patents:
U.S. Pat. No. 370,370 to Blair is directed to a camera plate holder for holding photographic film. That particular holder had a rigid frame, a central plate "c" (FIG. 4) with photographic film on both sides of the plate, a pair of slides "b" and "b'" and a pair of flexible cloth or rubber flaps "g" which are used to prevent the entry of light into the space between the dark slides b and b' and the photographic plate c itself.
U.S. Pat. No. 2,017,709 to Billing is directed to a carrier for photographic film, which carrier is made entirely of paper with inter-engaging stops operative between an inner envelope and outer envelope to prevent complete separation of the two envelope elements as a dark slide is removed to reveal the film. It states in column 1 of the Billing patent that the carrier and all its various parts are constructed of material which can easily be folded to a desired shape without cracking or breaking. As noted on page 2, lines 68 through 73, that particular carrier is specifically designed for a camera having a hinged back which serves to grip the carrier between the back of a camera and the opposed edge of the side wall of the camera.
U.S. Pat. No. 2,082,257 to Odell relates to a film holder which is made of paper or other lightweight material and which carries a piece of film in a light-tight manner. According to page 1, column 1, lines 11 through 19, the film holder in Odell enables a photographer to carry a large number of films of different character or sensitivity without the necessity of employing a bulky or heavy film holder. The film holder in Odell includes means for breaking the seal of the film holder to allow the film to be exposed once in the camera, but Odell is apparently silent on any way to reform the light seal around the film once the photograph has been taken.
U.S. Pat. No. 2,137,380 to Billing et al is directed to a film envelope similar to that shown in U.S. Pat. No. 2,017,709 described above.
U.S. Pat. No. 2,326,075 to Smith et al describes a film holder for photographic cameras having a relatively rigid, molded plastic frame. The main purpose of Smith et al is to maintain the distance between the back of the film and the camera as constant as possible to maintain the accuracy of the depth of focus.
U.S. Pat. No. 2,450,841 to Moore relates to a film holder for photographic cameras that can be economically manufactured. It has a rigid dye-cast frame capable of holding two sheets of film.
U.S. Pat. No. 2,497,270 to Panosian relates to a light seal for a photographic film holder. This patent points out that the increasing light sensitivity of photographic film had by 1948 made it increasingly difficult to manufacture a film holder such as those described above which were light-tight under all operating conditions (column 1, lines 39-43). The particular invention in Panosian is related a new construction which allegedly provided more space for the light seal than in previous film holders (column 2, lines 25-46).
U.S. Pat. No. 2,552,905 to Panosian is directed to film identifying means for photographic camera film holders and is a division of U.S. Pat. No. 2,497,270 described above.
U.S. Pat. No. 4,456,358 to Busch describes a film holder for field and studio cameras having automatic film loading elements to facilitate insertion and the positioning of the film within the apparatus.
The burden of carrying prior art film holders becomes progressively worse as the photographer's need for film increases. For example, a typical prior art film holder for a camera which uses 4" by 5" sheet film measures approximately 5" by 7" by 1/2". Such a holder weighs about 6.5 ounces and holds two sheets of 0.008" thick film. If the photographer wants to carry one hundred sheets of film, for example, fifty film holders would be needed. Fifty film holders of this size and weight would total 5" by 7" by two feet, and would weigh over twenty (20) pounds. That much bulk and weight is far beyond the amount a photographer would normally care to carry around, especially during work in the field or on location. On the other hand, the photographer despite this weight and bulk might on many occasions need and want more sheet film than can be easily carried. The burden of carrying a large number of prior art film holders is thus painfully evident.
At least one film/film holder combination is available which avoids some of these problems of weight and bulk. The film and the film holder are sold by Polaroid Corporation as various types of instant films under trade designation of Polaroid instant film and the recently introduced non-instant, conventionally processing Polaroid Chrome Film, all to be used with the Polaroid Film Holder Model 545. These film are individually factory packaged in a light tight envelope sealed on three sides and having an opening on the fourth side which is closed by metal double flaps, which also hold the sheet of film within the envelope without any other means of support. This film in the envelope is used with the 545 film holder, which has a slot therein for insertion of the envelope. First, this envelope is inserted into the 545 film holder and the film holder is in turn secured to the camera for the exposure of the film. Before the photograph is taken the envelope is withdrawn to uncover the film in the film holder. This motion does not move the film because the metal flap is at the time retained by a latch in the film holder. After photograph is taken with the prior art Polaroid system, the envelope is moved back to cover the exposed film and into the metal double flaps. The latch is manually released and the entire envelope with film within is removed from the film holder. In the case of the instant film the envelope is peeled open in halves to reveal the finished photographic print and the destroyed envelope and the metal flap are disposed of. In the case of the Polaroid Chrome Film, the envelope is later withdrawn in a darkroom to remove the film within for processing in conventional manner and the envelope and the metal flap are disposed of.
The envelope of the Polaroid Film is not reusable. That is, the photographer is not able to reload the Polaroid film envelope with relatively inexpensive bulk sheet film offered by other manufacturers. Also the prior art sheet film holder by virtue of its design traps dust easily. It is relatively difficult and time consuming to remove the dust once it gets inside, thereby making the task of cleaning the film holder most dreary, but absolutely necessary in order to avoid the further aggravation later on.